1. Field of the invention
This invention relates to containers having easy open closure systems.
2. Discussion of the Prior Art
Brochman, U.S. Pat. No. 4,372,460 describes an easy opening closure system comprising a container end portion having an opening therein; an exterior tape which comprises a backing and a pressure-sensitive adhesive layer and is situated circumjacent the opening; and a protective tape which comprises a barrier layer that provides a barrier to essential oils contained in beverages and an oil-resistant thermoplastic adhesive layer, the protective tape being firmly bonded to the bottom surface of the container end portion circumjacent the opening by means of the thermoplastic adhesive layer and to the exterior tape in the area of the opening by means of the pressure-sensitive adhesive layer and the thermoplastic adhesive layer. Although this type of closure system is widely used in the industry, it has been found that puncture of the barrier layer of the protective tape frequently does not occur when the closure is opened. Consequently, in order to gain access to the contents of the container, the consumer must puncture the barrier layer with a knife, fork, or like utensil. At present, failure of puncture occurs about 5 times out of every 100 containers. It is desired that this failure to puncture not occur more than 1 out of 100 attempts.
Accordingly, it is desired to provide a treatment or a modification of the closure system of the type described in U.S. Pat. No. 4,372,460 in order to minimize the above-described failure.